= How do I scatterplot observations which have the same set of co-ordinates? = Sometimes the same co-ordinates are shared by more than one observation. A scatterplot will only, however, show one point for each unique x,y combination regardless of the number of observations that share this combination. One way of disentangling this is to add a proportionately small amount to the observed values of one of the variables, say, y. The below syntax uses the rv.uniform function in SPSS to add a small random amount to the y values when an x,y combination has previously occurred. The new values which are now all unique (ynew) can then be plotted against x. {{{ sort cases by x. exe. sort cases by y. exe. COMPUTE copy=0. DO IF ($CASENUM NE 1). IF (x EQ LAG(x) AND y EQ LAG(y)) copy = 1. END IF. EXECUTE. compute ynew = y. if (copy eq 1) YNEW = Y + RV.UNIFORM(Y*0.01,Y*0.015). EXE. }}}